With the advent of a variety of effective childhood vaccinations, we now have very low rates of many of once deadly childhood diseases. However, they haven't completely disappeared. The bacteria and viruses that cause them are still around—in the United States and elsewhere in the world—so it's extremely important that children are properly vaccinated.

A number of these vaccines are given in combination. As noted earlier in this section, MMR is a vaccine against measles, mumps, and rubella. DPT is a vaccine against diphtheria, pertussis (whooping cough), and tetanus. Flu, hepatitis A and B, polio, and chickenpox vaccines are also available to prevent against those diseases.

Infectious Knowledge

According to the Centers for Disease Control & Prevention (CDC), the following is the recommended childhood immunization schedule.

Hepatitis B: Four doses total. The first one at birth, the second at least a month later, the third 12 weeks after that, and the final dose after the baby is at leastsix months old. (See Viral Hepatitis for more on Hepatitis B.)

Diphtheria, pertussis, tetanus (DPT): Starting at two months, again at four months, and a third dose at six months. The fourth dose must be at least six months after the third dose. A booster is recommended at age 11, with a routine booster every ten years afterward.

Flu: The first flu shot can be as early as age two months. After that, annual vaccination should occur. A pneumococcal vaccine that prevents 60 to 70 percent of bacterial pneumonia is given with the flu vaccine when the child is two.

Polio: Four doses at two months, four months, six to eighteen months, and four to six years.

Measles, mumps, rubella (MMR): The first dose is at one year. The second dose is recommended at four to six years.

Chickenpox: Vaccine at one year.

Hepatitis A: Recommended for certain states and regions and for high-risk groups. Ask your doctor whether your child needs this vaccine. (See Viral Hepatitis for more on this disease.)